My Only One

Composer

• 
  Choi Chul Ho

Director

• 
  Hong Seok Goo

Screenwriter

• 
  Kim Sa Kyung

Main Role

• 
  Choi Soo Jong

  Kang Soo Il / Kim Yoong Hoon

  Main Role
• 
  Uee

  Kim Do Ran [Soo II's daughter]

  Main Role
• 
  Lee Jang Woo

  Wang Dae Ryuk

  Main Role
• 
  Yoon Jin Yi

  Jang Da Ya [Yi Ryuk's girlfriend]

  Main Role
• 
  Jung Eun Woo

  Wang Yi Ryook [Dae Ryuk's younger brother]

  Main Role
• 
  Na Hye Mi

  Kim Mi Ran [Do Ran's younger sister]

  Main Role
• 
  Park Sung Hoon

  Jang Go Rae

  Main Role

Support Role

• 
  Lee Hye Sook

  Na Hong Sil [Da Ya's mother]

  Support Role
• 
  Jin Kyung

  Na Hong Joo [Da Ya's aunt]

  Support Role
• 
  Jung Jae Soon

  Park Geum Byung [Dae Ryuk's grandmother]

  Support Role
• 
  Cha Hwa Yun

  Oh Eun Young [Dae Ryuk's mother]

  Support Role
• 
  Park Sang Won

  Wang Jin Kook [Dae Ryuk's father]

  Support Role
• 
  Hwang Geum Byul

  Miss Jo [Wang family housekeeper]

  Support Role
• 
  Kim Chu Wol

  Yeo Joo Daek [Wang family's housekeeper]

  Support Role
• 
  Im Ye Jin

  So Yang Ja [Do Ran's mother]

  Support Role
• 
  Lee Doo Il

  Kim Dong Cheol [Do Ran's father]

  Support Role
• 
  Im Se Ju

  Yu Jin [Do Ran's friend]

  Support Role
• 
  Park Sook Myung

  [Hong Sil's housekeeper]

  Support Role
• 
  Lee Yong Yi

  Geum Ok [Yoo Jin's grandmother]

  Support Role
• 
  Lee Seung Hyung

  Chief secretary Yang

  Support Role
• 
  Kim Gwang In

  Doctor Kim

  Support Role
• 
  Go Woo Ri

  Jang So Young [JS Group President's daughter]

  Support Role
• 
  Go Wook

  Lee Tae Poong [Bakery employee]

  Support Role
• 
  Kang Doo

  Park Dong Won [Soo Il's inmate]

  Support Role
• 
  Kim Chang Ho

  Assistant Hong

  Support Role
• 
  Jung Tae Ya

  Jang Dae Ho [Go Rae & Da Ya's father]

  Support Role
• 
  Yook Mi Ra

  Go Yeong Sook [Eun Young and Hong Shil's friend]

  Support Role
• 
  Kim Hee Ryeong

  Kyeong Ja [Eun Young and Hong Shil's friend]

  Support Role
• 
  Goo Gyo Ik

  Kang Joon Soo [Da Ya's ex-boyfriend]

  Support Role
• 
  Kim Sun Kyung

  Shin Yeong Ae

  Support Role
• 
  Kang Chul Sung

  Kim Soo Hyeok

  Support Role
• 
  Song Joon Hee

  Kim Dong Cheol [Young]

  Support Role
• 
  Ji Yeon U

  Wang Jin Gook [Young]

  Support Role
• 
  Lee Sang Goo

  Father Peter

  Support Role
• 
  Im Ji Young

  [Do Ran's second trial prosecutor]

  Support Role
• 
  Kim Joo Young

  Chef Kim

  Support Role
• 
  Kim Mi Hye

  [Kim Mi Ran's friend]

  Support Role
• 
  Lee Gyeong Shim

  So Yang-Soon

  Support Role
• 
  Ham Jin Sung

  [Jang Go Rae's friend]

  Support Role
• 
  Kang Hyun Jung

  Nurse Park

  Support Role

Guest Role

• 
  Lee Jun Seo

  Kang Soo Il [Young]

  Guest Role
• 
  Choi Na Moo

  [Da Ya's flower shop employee]

  Guest Role
• 
  Min Joon Hyun

  Gyo Do Gwan [Prison officer]

  Guest Role
• 
  Kang Joo Ha

  Mi Ran [Young]

  Guest Role
• 
  Moon Ki Young Guest Role
• 
  Hong Boo Hyang

  [Resstaurant owner]

  Guest Role
• 
  Park Hyun Jung

  Yeon Yi [Do Ran's biological mother]

  Guest Role
• 
  Park Ha Na

  Seong Soo Hyeon [Daughter of Q Pharmaceuticals' CEO]

  Guest Role
• 
  Park Seong Kyun

  [Restaurant manager]

  Guest Role
• 
  Choi Dae Chul

  Jang Dae Ho [Go Rae and Da Ya's father]

  Guest Role
• 
  Yoon Joon Yeol

  [Middle school student circulating Dae Ryook's photos on a USB stick]

  Guest Role
• 
  Song Hyun Jin

  [employee at Haesung Ilsoo]

  Guest Role
• 
  Song Jung Woo

  Driver Kim

  Guest Role
• 
  Lee Young Suk

  Noh Sook Ja [Loan shark]

  Guest Role
• 
  Kim Joo Ryoung

  Park Mi Ok [Fake Myung Hee]

  Guest Role
• 
  Jung Heon

  Seung Joon [Go Rae's friend]

  Guest Role
• 
  Kim Kyu Chul

  Jang Dae Hun [Dae Ho's older brother]

  Guest Role
• 
  Jang Dae Woong Guest Role
• 
  Park Geon Rak

  [Nurse at nursing home]

  Guest Role
• 
  Lee Chae Kyung

  [Hong Shil's sister-in-law]

  Guest Role
• 
  Kim Oh Bok

  [Man talking in men's bathroom]

  Guest Role
• 
  Chae Yoon Hee Guest Role
• 
  Kim Nak Gyun

  [Detective]

  Guest Role
• 
  Lee Soo Yeon

  [ER Nurse]

  Guest Role
• 
  Lee Na Yeon

  [Amusement park girl]

  Guest Role
• 
  Song Chang Gyu

  [Truck dealer]

  Guest Role
• 
  Kim Seon Gyeong

  [Restaurant owner]

  Guest Role
• 
  Kim Su In

  Kim Do Ran [Child]

  Guest Role
• 
  Yang Hee Jae

  [Invited to birthday party]

  Guest Role
• 
  Jeon Hae Ryong Guest Role
• 
  Lee Jung Sung

  Lawyer Park

  Guest Role
• 
  Kim Seung Hyun

  [Su Jeong's brother]

  Guest Role
• 
  Lee Ho Jae

  [Lee Tae Poong's grandfather]

  Guest Role
• 
  Kim Joo Ah

  [Food cart owner]

  Guest Role
• 
  Shin Chi Young

  [Genetic testing staff]

  Guest Role
• 
  Lee Joo Bin

  Lee Soo Jung [Restaurant employee]

  Guest Role

Unknown

• 
  Cha Se In Unknown
• 
  Shin Se Rin Unknown
• 
  Kim Yoo Joon Unknown
• 
  Yoon Ji Won Unknown
• 
  Kim Yong Wan Unknown
• 
  Seo Jung Won Unknown
• 
  Jeon Seong Hun Unknown
• 
  Ban Hye Young Unknown
• 
  Kim Hye Ran Unknown
• 
  Kang Hak Soo Unknown
• 
  Yoon Se Eun Unknown